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Hybrid Cocoa Beans Dryer for Student Design Competition 2013

Contact Information

University: University of Yaounde

Team Members (with year of graduation): (1) MELI  TEDONG CYRILLE, (2) MOTCHEYO WOUNGWA STEPHAN YANNICK, (3) MAKAM LONLA AURELLE

Faculty Advisers: Dr. André Talla

Email Address: andre_talla@yahoo.fr

Submission Language : English

Project Information

Title: Hybrid Cocoa Beans Dryer

Description:

Abstract


The path of coffee-cocoa constitutes a vital sector for the economy of the tropical countries. They represent more than 46% of the export earnings and employ more than 2/3 of the population. The conservation of the cocoa is very difficult because of the unfavorable climatic condition during the production.  The objective of the project is the development of  a hybrid cocoa beans drier  able to dry cocoa beans during any season (rainy and dry season) and to produce a cocoa of good qualities and to reduce considerably the drying duration. The impacts of this project are :firstly the economic impact is obviously  the increase of the Cameroonian economy has by the increasing  the export earnings, secondly  the hygienic and medical level impact,  to produce a cocoa of good qualities free from smoke, insects and petroleum products such as the tar and asphalt, thirdly  the social impact , the raising of prices  of the cocoa, increase in the plantations and thus in the farmers.

Project Introduction


Last December a shipment of 3000 tons cocoa was turned over by the European Union because the cocoa was of bad quality, due to the contamination by smoke, petroleum products, pesticides and insects.  Following this bad quality, the farmers make also faced the problem of conservation of the cocoa because of the climatic conditions of the cocoa thus the objective of this project is the development of a double energy drier (biomass and solar) able to dry cocoa beans during any season, making it possible to obtain a cocoa of good quality complying with the rules of the market of the cocoa.


The hardware (MYDAQ) will be deployed for data acquisition.

Software (LABVIEW) will be used to provide orders to the ventilator by increasing the power of this last in order to increase the air velocity of drying, moreover it will enable us to decide if it is necessary to use the primary or secondary hot air generator according to the temperature in the room of the warm air solar heater, in nap it will enable us to automate the process of drying cocoa beans. 

Design Methodology


The mechanism of drying the cocoa beans is based on the principle of heat transfer by forced convection and more precisely a drier with fluidized bed. Principle:   Fluidization makes it possible to confer on granular solid properties similar to those of a liquid. Fluidization results from a dynamic balance between the particles of product and gas in upswing.  When one injects drying air at the bottom of a layer of product resting on a perforated sheet.

Phases of the process

  1. · Once the air heated, it will be necessary to know its temperature at the entry of the drying room;
  2. · To control the temperature in the drying room; 
  3. · To control the moisture of the air ;
  4. · To control the velocity of the fan.

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Products


Materials:

  1. · MYDAQ ;
  2. · LABVIEW ;
  3. · FAN;
  4. · HEATERS ;
  5. · SENSORS ;
  6. · FLOWMETER.

Design Architecture

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Functional Description

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Furnace heating mathematical Model

Our furnace heater process is based on the principle of a boiler, firstly there is a combustion reaction (oxidation of biomass), the products of this reaction are hot gases, and secondly these gases pass through a heat exchanger where they exchange with the drying air.


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From (6.) we know exactly the amount of energy to increase the drying air temperature.

From (4.) and (5.) we can even get with our LABVIEW program the amount of biomass to burn and displace the value on the control panel for the user.

Air flow rate regulation mathematical Model


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Drying Mathematical Model[3,4]

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Results and Discussion


A calling to what is described previously our system is made up of four  subVIs, but we could program and simulate just two of them because of the lack of equipment, but we have the intention to finish the entire program in the future.


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Our challenges were the lack of equipment and more training on LABVIEW programing, to solve this challenges we downloaded notes on LABVIEW programing and try to do a simulation of two subVIs as you can see the front panels and block diagrams, with the help of our mentor.

Conclusion


If agricultural products such as cocoa beans are not dried in suitable conditions, such as mold, discoloration, odor and taste disturbance unintended consequences occurs,

In this study  designing and simulation were done to see the most economical and to see least harmful way the establishment of commercial size dryer developed. Dryers can provide all types of products suitable for drying. Different products can be dried by making appropriate changes at operator panel.

Carried out with the drying system for required every type agricultural products dryer can be obtained. Different production capacity needs can meet by changing the physical size of the drying system.

Acknowledgements


This application is supported by NI planet under the project producing a hybrid cocoa beans dryer  was carried out. Thanks to Associate professor Dr.Talla Andre and  Mr Tarek Berro who helped us in this study.

References


  1. · [1] Thermique solaire octobre 2003 , Yves Jannot;
  2. · [2] Thermodynamics an engineering approach book, Yunus A.cengel and Micheal A. Boles ;
  3. · [3] C. Chongwen and Z.Wenxue, Computer Simulation of Agricultural Drying Process , China Agriculture Press, Beijing, China, 2001;
  4. · [4] Q. Liu, Stochastic Modeling and Automatic Control of Grain Dryers: Optimizing Grain Quality, Michigan State University, 1998;
  5. · NI training ISS 2013;
  6. · Cours d’initiation au logiciel labVIEW by Nicolas POUSSET.

Comments
Agroindustrial
Member
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Congratulations for your good job! Greetings from Perú.

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